-If you have any questions, I will be pleased to answer them at the end of the presentation.

-there will be time at the end of the presentation to answer your questions-so please feel free to ask me anything then.

-Don't hesitate to interrupt if you have a question.

-Please feel free to interrupt me at any time.

-Please stop me if you have any questions.

-If you need clarification¹ on any point, you're welcome to ask questions at any time.

-Can I come back to that point later?

-I will be coming to that point in a minute.

-That's a tricky² question.

-We will go into details later. But just to give you an idea of...

-I am afraid there's no easy answer to that one...

-Yes, that's a very good point.

-Perhaps we could leave that point until the questions at the end of the presentation

-I think I said that I would answer questions at the end of the presentation---perhaps you wouldn't mind waiting until then.

-I think we have time for just one more question